Cabinet interlock mechanism

ABSTRACT

The invention provides a mechanism for interlocking the pull-out drawers or shelves of a storage cabinet so that when a specified drawer or shelf is pulled out, the remaining drawers or shelves are interlocked in a closed or retracted position. The invention constitutes an improvement over the invention of U.S. Pat. No. 3,404,929 in that it permits the arrangement and number of drawers or shelves in a cabinet to be varied without having to replace the interlock bar.

United States Patent 1191 Dean et al. Feb. 18, 1975 [5 CABINET INTERLOCKMECHANISM 3,404,929 10/1968 Wright et al 312/216 [75] Inventors: Carl J.Dean, Charlton; David M.

Wright, Shrewsbur Bernard T. Primary Examiner-James C. Mitchell y i aCournoyer, Holden, all of Mass. Attorney, Agent, or FirmM1|ton E.Gilbert [73] Assignee: Barry Wright Corporation,

Watertown, Mass. [57] ABSTRACT [22] Flled: sept' 1973 The inventionprovides a mechanism for interlocking [21] Appl. No: 401,385 thepull-out drawers or shelves of a storage cabinet so that when aspecified drawer or shelf is pulled out, the [52] U S Cl 312/216remaining drawers or shelves are interlocked in a [51] 65/46 closed orretracted position. The invention constitutes 58 h H an improvement overthe mventlon of US. Pat No. leld of Seal-c 312/216 221 3,404,929 1n thatit permits the arrangement and num- [56] References Cited ber of drawersor shelves in a cabinet to be varied without having to replace theinterlock bar. UNITED STATES PATENTS 3,325,234 6/1967 Lewin 312/219 7Claims, 9 Drawing Figures iiiiit l FATENTH] FEB I 81975 sum 10F 4FATENTEU FEB I 8 I975 SHEU 3 OF 4 PATENIEDFEB 1 8197s SHEET nor 4CABINET INTERLOCK MECHANISM This invention relates to the interlockingof selected moveable units of a storage system, and more particularly tothe interlocking of drawers and other pull-out components of a storagecabinet.

BACKGROUND OF THE INVENTION It is often desirable to prevent selectedrnoveable units of a system from moving independently of one another.Such is the case where a specified storage unit, e.g., a drawer orpull-out shelf, of a filing cabinet has been pulled out. The remainingunits of the cabinet are desirably interlocked in a closed or retractedposition, so as to prevent them from being pulled out and therebyinterfering with access to the specified unit or causing the cabinet totip over and spill its contents and possibly injure the user ofbystanders.

US. Pat. No. 3,404,929, issued /8/68 to David M. Wright and Carl J. Deanfor Interlocking of Selected Units ofa Storage System discloses aninterlock mechanism for storage cabinets which employs a slidablevertically extending locking bar that spans a plurality of storage unitsand cooperates with cam assemblies mounted on each storage unit toeffect the desired interlocking. The lock bar has a plurality of lockingpins, one for each storage unit, and the cam assemblies of the severalunits are proportioned to engage the associated locking pin on thelocking bar. When a specified storage unit is pulled out, its camassembly engages the corresponding locking pin and thereby cams thelocking bar so that the cam assemblies of the other storage units areblocked by the other locking pins, whereby these other storage units areheld locked until the specified storage unit is restored to its normalretracted position. The mechanism also is designed to protect againstaccidental release of the interlocked mechanism.

Although the above-described prior art interlock mechanism is simple andeffective, it has a severe limitation. It happens that many users ofstorage cabinets with multiple pull-out storage units have unique or special requirements with respect to the number, type and size of pull-outcomponents. Fabrication of an interlock for each different arrangementof pull-out component requested by customers involves provision of manydifferent locking pin arrangements. This is ex pensive and timeconsuming and contrary to mass production principles. Furthermore, manyusers desire that the cabinets be so designed as to permit them toeasily change the spacing between and the relative positions of thepull-out components, and even to permit installation of additionalcomponents. However, the interlock mechanism disclosed in U.S. Pat. No.3,404,929 employs locking pins that are fixed to the locking bar. Hence,repositioning of drawers or other pull-out components by the user mayresult in a locking pin being in a position relative to a pull-outcomponent that prevents effective operation of the interlock system.

Accordingly, the primary object of this invention is to provide aninterlock mechanism for pull-out components of a storage cabinet thatovercomes the abovedescribed limitation ofthe mechanism disclosed in US.Pat. No. 3,404,929.

Another object of the invention is to provide an improved interlocksystem of the type described which is adapted to accommodate differentarrangements of pull-out and fixed storage components without having toemploy different lock bars and is adjustable to preserve effectiveinterlock operation when the arrange ments of storage components ischanged by the user.

Still a further object is to provide an interlock mechanism of the typedescribed which is adapted for use in cabinets with verticallyadjustable pull-out storage units.

A more specific object is to provide an interlock system formulti-component storage cabinets which has the same advantages butimproves upon the mechanism disclosed in U-.S. Pat. No. 3,404,929.

Other objects of the invention are rendered obvious by the descriptionwhich follows.

SUMMARY OF THE INVENTION The interlock mechanism of this inventioncomprises at least one locking bar assembly which is slidably disposedalong one side of the cabinet and spans one or more vertically displacedpull-out storage components. The locking bar assembly comprises aslidable locking bar and one or more locking pin sub-assembliesaccording to the number of pull-out storage components to beinterlocked. Each locking pin sub-assembly is adapted to be shiftedlengthwise of the locking bar and comprises a locking pin and means forreleasably lock ing the locking pin to the locking bar in a selectedposition for interaction with a storage component. Each pull-out storagecomponent includes a cam assembly which is disposed for interaction witha corresponding locking pin. Each cam assembly is designed so that whenthe associated storage unit is withdrawn, i.e., pulled out, the camassembly engages the corresponding locking pin and cams the locking barvertically to a position in which the cam assemblies of the otherpull-out units are blocked by the other locking pins, whereby the otherunits are locked in their retracted or closed positions until thewithdrawn unit is restored to its retracted or closed position. Otherfeatures, aspects and advantages of the invention are disclosed in orrendered obvious by the following detailed description taken inconjunction with the drawings.

THE DRAWINGS FIG. 1 is a perspective view, with a certain part brokenaway, of a multi-shelf storage cabinet embodying a preferred form ofinterlock mechanism constructed in accordance with the invention;

FIG. 2 is a sectional view in side elevation on an enlarged scale of thecabinet of FIG. 1;

FIG. 3 is a fragmentary exploded perspective view showing one of theside suspension units associated with a pull-out component;

FIG. 4 is a fragmentary perspective view showing a side suspension unitengaged with the locking bar assembly;

FIG. 5 is an enlargement of a sectional view taken along line 5-5 ofFIG. 2;

FIG. 6 is a fragmentary plan view, with a part broken away, of a lockingbar assembly;

FIG. 7 is a view in side elevation of a locking bar and the detentelement that is affixed to its upper end;

FIG. 8 is a perspective view of one of the locking pin sub-assemblies;and

FIG. 9 is a side elevation of a cam assembly.

Turning to the drawings, FIG. 1 illustrates a file cabinet 2 whichincorporates an interlock mechanism constructed in accordance with thepresent invention. The cabinet 2 consists of a top wall 4, opposite sidewalls 6 and 8, a rear wall 10 (FIG. 2), a bottom wall 11 (FIG. 2), and afront base panel 12 which are interconnected to form an integralstructure. Side panels 6 and 8 have right angle flanges 13 at theirfront ends. The cabinet also includes a self-storing door which in thiscase is in the form of a tambour 14 and made up of a plurality ofinterlocked and hinged slats 15 (FIG. 2) and a handle bar 16. In FIG.lt'he tambour is in its open or stored position. The cabinet comprises atier of pull-out shelves 17. For convenience of illustration, only twoshelves 17 are illustrated in FIG. 1. However, it is to be appreciatedthat additional shelves may be accomodated by the cabinet. Also,although not shown, it is to be understood that the pull-out shelves maybe replaced by pull-out drawers. Each pull-out shelf is mounted on apair of conventional suspension arm units which are identified generallyin FIG. 1 by the numeral 18. The cabinet also includes an interlockmechanism identified generally by the numeral 20 which is illustrated ingreater detail in the other figures of the drawing.

Referring now to FIGS. 1 and 2, the tambour 14 is guided at its sideedges so that it can be raised or lowered so as to reveal or conceal thepull-out shelves. In FIG. 2, the tambour 14 is shown in its closedposition. The construction of the tambour l4 and the means for guidingit form no part of the present invention; nevertheless, certain detailsof the guide means for the tambour are described hereinafter in order tofacilitate understanding of the present invention.

Referring now to FIG. 2, an outer track member is mounted to side wall8. This track member comprises an upper horizontal section or run 19Aand front and rear vertical sections or runs 198 and 19C respectively.This track member is of angle iron, i.e., L-shaped, cross-section, withone angle portion 21 being parallel to the side wall and the other angleportion 22 extending at right angles to the side wall and acting as anouter guide or track for the tambour. An inner top-track assembly 24also is mounted to the side wall. The track assembly 24 comprises aplate 26 with a right angle flange 28. The latter extends parallel tothe portion 22 of the horizontal outer track section 19A and acts as aninner or lower top guide or track for the tambour 14; Also attached toside wall 8 are two upright members 30 and 32. These two uprights areessentially channel members, consisting of body portions 34 which arespaced from the adjacent side wall, plus opposite side wall portion 35having flanges 37 which are secured to the side wall. The angle portions21 of the outer track member sections 198 and 19C overlap and areaffixed to the flanges 37 of the front and rear side wall portions ofuprights 30 and 32 respectively as shown in FIGS. 2 and 3. The frontside wall portion of the front upright 30 acts as an inner front guideor track for the right hand edge of tambour 14, while the rear side wallportion of the rear upright 32 acts as an inner rear guide for the sametambour edge. Thus the right hand edge of the tambour l4 rides betweenand is guided by the portions 22 of the outer track sections 19A-C, andthe flange 20 of the inner top track assembly and the front and rearside wall portions respectively of uprights 30 and 32 as it is raised orlowered. The inner top track assembly 24 also includes a sprocket 38which is rotatively mounted to its plate 26 and engages interlockingportions of the tambour slats 15. The rear end of track assembly 24 alsocomprises a rear guide 40 attached to plate 26 which acts as atransition between flange 28 and the rear side wall portion of rearupwright 32. Sprocket 38 and guide 40 assure that the tambour will notbind as it is raised and lowered.

Although side wall 6 is not shown in the same detail as side wall 8, itis to be understood that it is provided with a corresponding arrangementof track sections 19A-C, track assembly 24 and uprights 30 and 32 asshown in FIG. 2, with the result that the left-hand edge of tabmour 14is guided in the same way as the right hand edge.

The uprights 30 and 32 on each of the walls 6 and 8 are provided with aseries of vertically spaced horizontally elongated slots 42. These slotsserve to position the suspensions for the various pull-out shelves.Referring now to FIG. 3, each of the pull-out shelves 17 comprise a rearwall 44, a bottom wall 45, and opposite side walls 46. Although notshown, it is to be understood that each side wall of the shelf isattached to a suspension arm unit 18. For this purpose each side wall 46is provided with a pair of hook-like mounting tabs 48 which are punchedout of the side walls. Each of the two suspensions 18 for each of thepull-out drawers comprises three telescoping arms 50, 52 and 54 with thearm having a pair of slots 56 (only one of which is visible in FIG. 3)to accommodate tabs 48. The tabs interlock with arm 50 so that shelf 17can move with arm 50 as the latter telescopes relative to arms 52 and54. As shown in FIG. 5, the arms 50, 52 and 54 are slidably connected byball bearings 57. Each suspension arm 54 is provided with two pairs ofmounting tabs 60 (FIG. 3) for interlocking with pairs of slots 42 inuprights 30 and 32. The tabs 60 are hook-shaped and after they areinserted in selected one of the slots 42, the suspension arm 54 isshoved rearwardly so that the tabs will interlock with the uprights 30and 32. Then, while arms 50-54 are extended as shown in FIG. 3, a sheetmetal retaining screw 62 engaged in a hole (not shown) in arm 54 isscrewed up so that it engages the rear flange of the front upright 30,thereby locking suspension arm 54 against movement relative to theupright and the adjacent side wall.

It is to be understood that the suspension arms shown in the drawing areof conventional design and suspension arms of other known design may beused to mount the shelves for pull-out action. In any event, eachpullout shelf is supported by a first suspension arm assembly attachedto the uprights on cabinet side wall 8 and a second suspension armassembly attached in a similar manner to the uprights on the oppositecabinet side wall 6. Obviously, the height of each of the pull-outshelves can be adjusted by raising or lowering the suspension armassemblies with respect to the uprights 30 and 32 at each side of thecabinet. This permits a variable number of pull-out shelves or drawersto be mounted in the cabinet, and also the use of pull-out shelves ordrawers of different vertical dimensions.

Referring now to FIGS. 1, 3, 5 and 9, the interlock mechanism includeslike cam assemblies associated with each pull-out shelf which cooperatewith pins on the locking bar assembly hereinafter described. The camassemblies employed in the preferred embodiment of the inventionandillustrated in the drawings are substantially the same as the onesillustrated and described in said US. Pat. No. 3,404,929. Each camassembly consists of an upper cam member 64 and a lower cam member 66.The upper cam member has two intersecting ramp surfaces 68 and 70 and anend surface 72. The lower cam member has oppositely sloping rampsurfaces 74 and 76 separated by a horizontal surface 78. The cam membersare spaced apart so as to define a channel 80 between surfaces 70 and 74that is wide enough to allow movement therethrough of a locking pin asthe associated shelf is pulled-out and pushed back again to its closedposition. These cam members are attached to the pull-out shelf on theside wall adjacent to the locking bar assembly, and are located abovethe level of the associated suspension arm unit. They may be made ofmetal or various other materials such as those mentioned in said US.Pat. No. 3,404,929.

Referring now to FIGS. 2 and 4, the illustrated preferred embodiment ofthe interlock mechanism comprises a locking bar guide in the form of aU-shaped vertically extending channel member 84 that is affixed tocabinet side panel 8 between uprights 30 and 32 but adjacent to upright30. Slidably disposed in the open vertical channel defined by channelmember 84 is a slidable locking bar assembly that comprises an elongatelocking bar 86 in the form of a flat C-shaped channel member. Moreparticularly, locking bar 86 consists of a flat body portion 88 andparallel flat opposite side walls 90 that extend at right angles to bodyportion 88 and have integral right-angle flanges 92. Locking bar 86 andits guide 84 are sized so that the former makes a close sliding fit inthe latter and so that the front surfaces of flanges 92 are at leastflush and preferably project beyond the front edges of the sides ofguide 84. The locking bar may be retained in guide channel member 84 byslidable retaining means, e.g., straps attached to the sides of thechannel member and extending across and in front of the locking bar,located at the upper and lower ends of the guide member. However, suchretaining means are not absolutely required since the upper end of thelocking bar is engaged with a detent means hereinafter described and theremainder of the locking bar is slidably retained at various points byengagement of the suspension arm units that are attached to the adjacentside wall of the cabinet with the locking pin sub-assemblies hereinafterdescribed. Nevertheless, to hold the locking bar in channel member 84 inthe absence of any suspension arm units, it is preferred to provide aretainer in the form of a flexible L- shaped bracket 95 which is securedto cabinet bottom wall 11 and extends up inside of and lightly engagesthe bottom end of the locking bar.

The locking bar assembly also includes a plurality of locking pinsub-assemblies 94 carried by locking bar 86. One locking pinsub-assembly is provided for each pull-out shelf. Referring now to FIGS.2, 4, 5 and 8, each locking pin subassembly 94 comprises a spacer plate96 which is made up of a flat rectangular body portion 98, an offsetportion 100 and an inclined flange portion 102. Spacer plate 96 may bemade of plastic but preferably is made of sheet metal. In any event itis made of a fairly stiff yet resilient material so that its offset andflange portions can yield without breaking or undergoing permanentdeformation when engaged by a suspension arm unit as hereinafterdescribed. The body portion 98 is formed with four projections 104, onenear each of its four corners, which are similar in shape to a sectionof a sphere and thus have straight edges as shown. Where the spacerplate is made of metal, the projections are formed by pushing outsemicircular portions of the spacer body. In any event, pro

5 jections 104 function as locator or guide means to maintain the spacerplate so that its opposite side edges 106 (FIG. 8) extend parallel toside walls of locking bar 86. To this end, the projections are locatedso that they will fit between flanges 92 and so that their straight sideedges will slidably engage the adjacent edges of flanges 92. The bodyportion of each spacer plate also is formed with a centrally locatedcircular boss 108 (FIG. 5) which projects oppositely to projections 104and has a center hole.

Each locking pin sub-assembly 94 also comprises a lock pin or stud 110which is formed with a hexagonal shaped flange 112 and a threadedextension 114. The lock pin is mounted to the spacer plate by insertingits threaded extension 114 through the hole in boss 108 so that thelatter is engaged by flange 112, and then screwing onto extension 114 anut 116. As seen best in FIG. 8, nut 116 is elongated in one dimensionso as to have straight opposite sides 118, and has a thickness less thanthe gap between each of the flanges 92 and body portion 88 of lockingbar 86. Additionally, the distance between its straight sides 118 isless and the length of each of said sides is greater than the gapbetween the confronting edges of locking bar flanges 92. As a result,the nut can be easily inserted between the flanges 92 if it is orientedso that its straight sides extend lengthwise of the locking bar, and canbe retained by the same flanges if it is oriented so that its straightsides extend at an oblique angle to the confronting edges of flanges 92.The straight sides of nut 1l6are made long enough so that the side walls90 of the locking bar will limit its rotation to less than 180.Preferably the nut is sized so that side walls 90 prevent it fromassuming an angle of greater than about 45 relative to the longitudinalaxis of the locking bar. Assuming that the locking pin subassembly ismounted to the locking bar in the manner described and illustrated, itcan be locked in any desired position merely by orienting nut 116 sothat it extends behind flanges 92 and then rotating the locking pinconveniently by applying a wrench or pliers to hex flange 112 so as toadvance its threaded portion in a direction to cause the nut and spacerplate to tightly engage flanges 92. To change the position of the spacerplate along the lock bar, all that is required is to loosen the nut,then slide the spacer to the desired position, and finally retighten thenut. Preferably but not necessarily, the end of the threaded extension114 may be peened or swaged over so as to form a head or flange whichwill prevent it from pulling out of the nut when unscrewing the lock pinto release the spacer plate.

Of course, for each pull-out shelf a certain positioned relationshipmust be maintained between the locking pin and the cams associated withthe adjacent side of the shelf, otherwise, the desired interlockingoperation will not be achieved. Since the location of the cams is fixedwith respect to the associated suspension unit, it is a relatively easymatter to locate each locking pin sub-assembly at the specific heightrequired for it to correctly engage the cams of a designated pull-outshelf. This adjustment is accomplished using the gauge template 120(FIG. 4) which has a channel portion 122 adapted to snugly embrace therear suspension arm 54 and an upstanding lip or flange 124. With thegauge template in place, thelock pin sub-assembly is lowered on lockingbar 86 until its lock pin is resting on lip 124. Then'the lock nut istightened and the gauge template is removed. By properly proportioningthe height of lip 124, the lock pin assembly will be in the correctposition for interaction with the cams of the associated pull-out shelfwhen lock pin 110 is moved against lip 124 of the gauge template.

The locking bar is movable vertically between two predetermined DOWN andUP positions which are determined by a detent mechanism consisting ofcooperating members-carried by the locking bar and inner top trackassembly 24. Referring now to FIGS. 2 and 5, a plastic wear plate 130 isattached to the upper end of locking bar 86, the latter being providedwith an aperture into which a portion of thewear plate is secured. Thefront side of the wear plate is provided with two offset surfaceportions 132 and 134 that are connected by a sloping surface portion136. The upper offset surface portion 132 is provided with two rounded,preferably circularly curved, grooves or sockets 138. Affixed to plate26 of track assembly 24 is a hollow member 140 that is open at one endand is closed off at the opposite end by an end wall 142. The latter hasan air exhaust port 143. Hollow member 140 projects through a hole inplate 26 and has an exterior flange 144 that is affixed to plate 26 byscrews 146 (FIG. 2). Slidably mounted within hollow member 140 is ahollow detent member 148 which is formed with a rounded ball-likeextension 150 sized to mate with grooves 138. A compression spring 151within member 140 urges detent member 148 into engagement with wearplate 130. In normal operation of the interlock mechanism, locking bar86 moves between a lower or DOWN position (FIG. 5) in which detentmember150 is seated in the upper one of grooves 138 and a higher or UPposition in which member 150 is seated in the lower groove. In each ofthese positions the bottom end of the locking bar is restrained againstmoving out of guide channel member 84 by bracket 95. If it is desired toremove locking bar 86 from guide channel member 84, the locking bar ispushed up manually far enough for the detent member to be forced back bysurface 134 of the wear plate and when this occurs the bottom end of thelocking bar will have cleared bracket 95. Thereafter the lower end ofthe locking bar is pulled out of guide member 84 far enough so that itwill not engage bracket 95 when it is subsequently lowered. Then thelocking bar is pulled down far enough to disengage wear plate 130 fromdetent member 150, whereupon the locking bar can be pulled fully free ofguide channel member 84.

Operation of the interlock mechanism will now be described. When all ofthe pull-out shelves 17 are in a closed position, as shown in FIG. 1,the locking bar is normally in its lower or DOWN position. When aselected shelf is withdrawn, the ramp surface 74 engages the adjacentlocking pin 110 and thereby cams the locking bar to its UP positionwhere it is held by the seating action of detent 150 on the lower groove138. With the locking bar in its Up position, each of the other lockingpins 110 is disposed in front of the front surface 72 of the upper cammember of the associated shelf. Consequently, the other shelves areblocked by their associated locking pins so that none may be pulled outinadvertently to cause the cabinet to tip.

When the withdrawn (i.e, pulled-out) shelf is returned to its closed(i.e., retracted) position, the cam surface of its upper cam member willengage the associated locking pin and thereby cam the locking bar backto its initial DOWN position.

If the locking bar should inadvertently fall from its UP position whenone of the shelves is pulled out, the cam surface 76 of the lower cammember of the withdrawn shelf will reengage the associated locking pinas the shelfis pushed back, thereby raising the locking bar and allowingthe locking pin to travel along surface '78 which guides it into channel80, whereupon the ramp surface 70 will again force the locking bar backto its DOWN position in the same manner as it would have if the lockingbar had not fallen inadvertently while the shelf was pulled out.

The bevel ramp surface 68 at the front of each upper cam provides somelatitude in locating the associated locking pin.

The snap action that characterizes the detent mechanism for the lockingbar is important since when the latter is in its DOWN position, asubstantial pulling force is required to pull out one of the shelves.Hence the locking pins and the ramps 74 of the several lower cam memberscoact to hold the shelves in their retracted positions until a pullingforce is exerted on one of the shelves great enough to force the lockingbar to overcome the hold-down force resulting from the coaction of theupper socket of the wear plate and detent mem her 150 under theinfluence of spring 151.

Although not shown, it is contemplated that the cabinet may be made witha keyed lock by which the shelves, drawers and other pull-outcomponents, may be sured in a locked position. The key lock mechanismmay be of the form described and shown in said US. Pat. No.- 3,404,929;that is, it may include a rotatable crank which interacts with suitablebracket means on the locking bar to shift the latter up and down andlock it in its UP position so that the several locking pins block thepull-out components and thus prevent them from being pulled out. Ofcourse, other forms of key lock mechanisms also may be employed toperform the same function.

It is contemplated also that the cabinet may embody two interlockmechanisms as herein described, one at each side of the tier of shelvesor drawers.

Persons skilled in the art will appreciate that the apparatus as hereindescribed and illustrated may be modified in various ways, such as bychanging the shape and arrangement of parts or by substitutingequivalent elements, without departing from the spirit and scope of theinvention as set forth in the appended claims.

What is claimed is:

1. In a filing cabinet containing at least two pull-out storagecomponents, apparatus for maintaining prescribed ones of said componentsin retracted position when a selected one of said components is pulledout to an extended position, comprising:

a slidable locking bar assembly spanning said pull-out components, saidlocking bar assembly comprising a locking bar, at least two lockingpins, one for each of said pull-out components, and lock meansreleasably securing said locking pins to said locking bar, said lockingpins being moveable lengthwise of said locking bar when said lock meansare released, said locking pins projecting laterally of said locking barinto adjacent relation with said pull-out components, and

cam means mounted on each of said pull-out components in position toengage the adjacent locking pin, said cam means each comprising a firstportion for engaging and camming the adjacent locking pin so as to movesaid locking bar in a first direction from a first unlocking position toa second locking position when the pull-out component on which said cammeans is mounted is pulled out to an open position, and a second portionfor engaging said adjacent locking pin so as to prevent the pulling outof the pull-out component on which said cam means is mounted when saidlocking bar has been moved to said second locking position by thecamming action of another of said cam means on another of said lockingpins.

2. Apparatus according to claim 1 wherein said cam means each comprisesa third portion for I) engaging said adjacent locking pin when saidlocking bar is in said second locking position and the pull-outcomponent on which said cam means is mounted is in a pulled-out positionand (2) camming said adjacent locking pin so as to move said locking barin a second direction to said first unlocking position when the pulloutcomponent on which it is mounted is moved to a closed position.

3. Apparatus according to claim 1 further including means formaintaining said locking bar in a discrete one of said first and secondpositions.

4. Apparatus according to claim 1 comprising a guide means for saidlocking bar, telescoping suspension arms attached to said cabinet andsupporting said pullout components, and spacer means slidably restrainedby said suspension arms for holding said locking bar in slidableengagement with said guide means.

5. Apparatus according to claim 4 wherein said spacer means is integralwith said lock means for releasably securing said locking pins to saidlocking bar.

6. Apparatus according to claim 1 wherein said locking pins each has athreaded extension; and further wherein said lock means for securingsaid locking pins to said locking bar each comprises a locking plateengaging one surface of said locking bar and having a hole through whichsaid threaded extension protrudes, and a nut screwed onto said threadedextension and engaging an opposite surface of said locking bar.

7. Apparatus in accordance with claim 2 wherein said cam means includesa fourth portion for (l) engaging said adjacent locking pin when saidlocking bar is inadvertently in said first unlocking position and therespective pull-out component on which said cam means is mounted is in apulled-out position and (2) camming said adjacent locking pin so as tomove said locking bar in said first direction to said second lockingposition be fore said third portion engages and cams said adjacentlocking pin so as to move said locking bar to said first unlockingposition.

1. In a filing cabinet containing at least two pull-out storagecomponents, apparatus for maintaining prescribed ones of said componentsin retracted position when a selected one of said components is pulledout to an extended position, comprising: a slidable locking bar assemblyspanning said pull-out components, said locking bar assembly comprisinga locking bar, at least two locking pins, one for each of said pull-outcomponents, and lock means releasably securing said locking pins to saidlocking bar, said locking pins being moveable lengthwise of said lockingbar when said lock means are released, said locking pins projectinglaterally of said locking bar into adjacent relation with said pull-outcomponents, and cam means mounted on each of said pull-out components inposition to engage the adjacent locking pin, said cam means eachcomprising a first portion for engaging and camming the adjacent lockingpin so as to move said locking bar in a first direction from a firstunlocking position to a second locking position when the pull-outcomponent on which said cam means is mounted is pulled out to an openposition, and a second portion for engaging said adjacent locking pin soas to prevent the pulling out of the pull-out component on which saidcam means is mounted when said locking bar has been moved to said secondlocking position by the camming action of another of said cam means onanother of said locking pins.
 2. Apparatus according to claim 1 whereinsaid cam means each comprises a third portion for (1) engaging saidadjacent locking pin when said locking bar is in said second lockingposition and the pull-out component on which said cam means is mountedis in a pulled-out position and (2) camming said adjacent locking pin soas to move said locking bar in a second direction to said firstunlocking position when the pull-out component on which it is mounted ismoved to a closed position.
 3. Apparatus according to claim 1 furtherincluding means for maintaining said locking bar in a discrete one ofsaid first and second positions.
 4. Apparatus according to claim 1comprising a guide means for said locking bar, telescoping suspensionarms attached to said cabinet and supporting said pull-out components,and spacer means slidably restrained by said suspension arms for holdingsaid locking bar in slidable engagement with said guide means. 5.Apparatus according to claim 4 wherein said spacer means is integralwith said lock means for releasably securing said locking pins to saidlocking bar.
 6. Apparatus according to claim 1 wherein said locking pinseach has a threaded extension; and further wherein said lock means forsecuring said locking pins to said locking bar each comprises a lockingplate engaging one surface of said locking bar and having a hole throughwhich said threaded extension protrudes, and a nut screwed onto saidthreaded extension and engaging an opposite surface of said locking bar.7. Apparatus in accordance with claim 2 wherein said cam means includesa fourth portion for (1) engaging said adjacent locking pin when saidlocking bar is inadvertently in said first unlocking position and therespective pull-out component on which said cam means is mounted is in apulled-out position and (2) camming said adjacent locking pin so as tomove said locking bar in said first direction to said second lockingposition before said third portion engages and cams said adjacentlocking pin so as to move said locking bar to said first unlockingposition.